From Emily's LPSC blog: "Bob Pappalardo would not sit down until he got Cleave to acknowledge that Europa is the consensus highest priority of the planetary science community."

Cleave was obviously poorly prepared for this session, but I don't see that this acknowledgement is either meaningful or particularly accurate. If Europa were the "highest priority" of the PS community as a whole, then one might wonder why we were spending all this money on Mars. I could easily imagine that Europa is the highest priority of the outer planets community, but frankly I was surprised when Europa Orbiter appeared in the '07 budget (presumably the result of some serious lobbying on someone's part.) It was pretty obvious to me then that there would be no money for it, especially in the aftermath of JPL running the old EO project into the ground with cost overruns and engineering upscopes. (And JIMO is best forgotten.)

Don't get me wrong, I would love to be involved with a Europa mission (we did what I think was a good proposal design for EO) but I don't see either the money or the political support being there in the near term. I know it's frustrating, but one has to be realistic, and it might help to avoid the aura of entitlement that I perceive is building in some parts of the community (not referring to you, Bob). Of course, I am just a lowly engineer.

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Disclaimer: This post is based on public information only. Any opinions are my own.

That was slightly sloppy reporting on my part, and I need to go back to my [illegal] recording to try to see exactly what Bob said. It generally appears that Mars is considered wholly separately from exploring the rest of the solar system (I am kind of curious how the financial priorities are set between the Mars program and everything else; I don't know anything at all about that).

Leaving out Mars, the Decadal Survey identified priorities for missions to other targets in the solar system, identifying one large class mission (assumed rate one per decade) and five medium class missions (assumed rate three per decade, with two extras listed) as being the top priorities of the science community. Europa stands alone in that large mission class. The five medium missions are, in order: Pluto/KB Explorer; lunar South Pole/Aitken Basin sample return; Jupiter Polar Orbiter with Probes; Venus In-Situ Explorer; and Comet Surface Sample Return.

One reason Bob wanted to stand up and say that yesterday is because he (and the rest of the Europa community) were alarmed by the possibility that Jonathan Lunine's provocative suggestions of Titan as being the one target he would explore if forced to choose one would be seen as "mixed messages" coming out of the outer planets community. Lunine's point is debatable, but as far as mission planning is concerned it's not really a relevant one. Planning out future missions requires not only looking at what questions scientists desire to answer but also the maturity of the field and the technological readiness to start a new mission. With Cassini still at Saturn it's not time yet to start a Titan mission now -- one would guess it would be a top candidate for the single large mission of the next decade, after Europa.

Doesn't look like NASA's too interested in considering large missions at all right now though.

If you're in your 20's - you have CassiniIf you're in your 30's - you had GalileoIf you're in your 40's - you had VoyagerIf you're in your 50's - you had Viking

yes yes - lots of overlap and doesnt really sit in those catagories properly, it's a metaphor more than a real survey of the past - but there's nothing for our teenagers - where is their Voyager? Has there been a point in the last 40 years when the next really big mission wasnt at least in the planning stages?

From Emily's LPSC blog: "Bob Pappalardo would not sit down until he got Cleave to acknowledge that Europa is the consensus highest priority of the planetary science community."

Cleave was obviously poorly prepared for this session, but I don't see that this acknowledgement is either meaningful or particularly accurate.

Frankly, it appears, at least to me, that Cleave may be poorly prepared for her job (AA/SMD). I don't mean this as an attack on her credentials, whatever those happen to be, but in light of the past few weeks, she seems to be increasingly isolated. First, Griffin holds in abeyance the Dawn cancellation pending "review," which seems to be a slap in Cleave's face, though this could just be a maneuver to buy some bureaucratic time. And now Cleave walks into the buzzsaw at "NASA Night." Given the reports of what transpired at the latter, I think Cleave would have confessed to the JFK assassination just to get off the podium

As for the substance of your post...

QUOTE (mcaplinger @ Mar 15 2006, 05:50 PM)

If Europa were the "highest priority" of the PS community as a whole, then one might wonder why we were spending all this money on Mars. I could easily imagine that Europa is the highest priority of the outer planets community, but frankly I was surprised when Europa Orbiter appeared in the '07 budget (presumably the result of some serious lobbying on someone's part.) It was pretty obvious to me then that there would be no money for it, especially in the aftermath of JPL running the old EO project into the ground with cost overruns and engineering upscopes. (And JIMO is best forgotten.)

As Emily alluded to in her post, what is "highest priority" even among the subset of outer planets specialists is becoming uncertain. And in addition to Titan as a rival target, I'm waiting for an Enceladus Underground to start coalescing.

Planning out future missions requires not only looking at what questions scientists desire to answer but also the maturity of the field and the technological readiness to start a new mission. With Cassini still at Saturn it's not time yet to start a Titan mission now -- one would guess it would be a top candidate for the single large mission of the next decade, after Europa.

But what if "the maturity of the field and the technological readiness," not to mention the funding, is not in the cards for the strawman Europa mission recommended by the Decadal Survey as the next Flagship-class mission? Do we have to wait to punch the ticket of these prioritized mission sets when, for example, other new targets may emerge during the interim? The problem with Decadal Surveys (or all long-term "roadmaps") is that they're usually not too discovery-driven. Of course, the hurdles (programmatic and technological) facing outer planetary exploration are much different than those facing Mars exploration, but I wonder whether a prioritization scheme similar to the Pathways/Next Decade approach used for Mars might be useful for the outer planets.

QUOTE (elakdawalla @ Mar 15 2006, 07:19 PM)

Doesn't look like NASA's too interested in considering large missions at all right now though.

I'm surprized that Ceres is not considered a high-priority medium class mission; seems like it should rank higher than lunar sample returns. Considering it's a carbonaceous chondrite class 'roid with potentially some past planetary evolution, it seems like a survey (and sample return?) from it could be far more interersting.

Or is Ceres still considered a "small" mission class? I thought Dawn kinda proved it should be funded as a medium class mission.

"aura of entitlement" is forming? This is 'merica! Aren't we entitled to everything, all the time, and neatly packaged in excessive + disposable packaging? I'd like the new & improved Europa Orbiter to go please, with a side of stardust-style-impactors and a large, orange drink! Yeah - and "biggie size" it!!

Not only did the 2002 Decadal Survey rank Europa as the highest-priority target for a large non-Mars planetary mission, but OPAG has just officially ranked it above Titan ( http://www.lpi.usra.edu/opag/oct_05_meetin...ting_report.pdf '. pg 2. OPAG officially ranks Titan second, above Neptune.) Lunine, in short, was engaged in trouble-making, and Pappalardo was entirely justified in doing what he did. (Mars is in an entirely separate category all by itself -- it's NASA's official Holy of Holies, never to be questioned on any ground.)

The question at this point is whether a combined Titan-Enceladus mission is possible, and whether this really might upend the current order.

This is basically what Mike said (viz., "If Europa were the 'highest priority' of the PS community as a whole, then one might wonder why we were spending all this money on Mars. I could easily imagine that Europa is the highest priority of the outer planets community...").

Not only did the 2002 Decadal Survey rank Europa as the highest-priority target for a large non-Mars planetary mission, but OPAG has just officially ranked it above Titan ( http://www.lpi.usra.edu/opag/oct_05_meetin...ting_report.pdf '. pg 2. OPAG officially ranks Titan second, above Neptune.) Lunine, in short, was engaged in trouble-making, and Pappalardo was entirely justified to do what he did. (Mars is in an entirely separate category all by itself -- it's NASA's official Holy of Holies, never to be questioned on any ground.)

The question at this point is whether a combined Titan-Enceladus mission is possible, and whether this really might upend the current order.

The strange thing is that Lunine didn't seem to think he was trouble-making, and just as Cleave doesn't understand why the scientists are angry, Lunine doesn't understand why the outer planets folks are feeling threatened by his public suggestion (though the Leonard David article should answer that).

People here seem to be pretty dismissive of the possibility of a combined Titan-Enceladus mission but of course no one is actually presenting either a suggestion for or rebuttal of such a possibility at any of the sessions.

What most of the outer planets folks are saying about Titan is that the surface should not be explored until it is well mapped from orbit. They are asking themselves whether a New Frontiers mission couldl be sent to Titan with only two instruments: a radar mapper capable of 100-meter resolution and a 2-micron imager. These are all geologists talking though, and I think that the mission would be more interesting to more people with a third instrument that could do a thorough map of the atmosphere, such as a limb sounder, to map hazes, clouds, etc. (I'm a new fan of limb sounders now that we're doing public outreach on the Mars Climate Sounder.) But of course I don't have a clue how much mass/complexity that would add to the simple orbiter that the outer planets folks are talking about.

What most of the outer planets folks are saying about Titan is that the surface should not be explored until it is well mapped from orbit. They are asking themselves whether a New Frontiers mission could be sent to Titan with only two instruments: a radar mapper capable of 100-meter resolution and a 2-micron imager.

So let me get this straight: the "outer planets folks" are pondering a New Frontier-class mission that wasn't even recommended in the Decadal Survey (i.e., the Titan concept you note above) while a subset of them are invoking the same Decadal Survey that lists Europa as the highest priority non-Mars Flagship-class target?

Sad to see all this intramural political wrangling interfering with the serious task of saving NASA's planetary exploration program. This very public lack of unity on the part of the planetary science community will only serve to justify the cuts in the minds of senior NASA and Bush administration leaders.

It's time to draft a consolidated, universally-supported agenda and start hammering it home to the bean-counters!!! I frankly don't care whether Europa, Titan, or Enceladus is chosen as the prime focus; the fact is that all of these bodies are worthy of Flagship-class missions, and the main goal should be to get such a mission funded. This petty bickering is undermining UMSF.

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A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.

I'm profoundly disturbed by the notion that the prioritization should be irrespective of means, as Emily has lightly touched upon, or readiness, as Alex has touched on.

If a cheapo mission that scored major Enceladus goals came to light, then it would seem in at least one sense to become a more sensible mission than a blockbuster to Europa or Titan. But we also have to strategize -- all three of these satellites are going to draw us into twenty questions games, and the best first mission to one of them is not necessarily the mission that returns the most gigabytes of science data from that one. Europa and Enceladus offer possible free-return (or very cheap return) missions. Enceladus and Titan offer the possibility (not that I can sketch one out) of a single mission that delivers some science from the other one. Of course, Europa is in proximity to other worlds of interest, also. Europa also happens to be closer to Earth for potentially shorter cruise, but is cursed with its position deep inside Jupiter's gravity well; maybe a Titan mission *could* get to Titan faster than a Europa mission could get to Europa. Meanwhile, most Europa mission designs would be sharply time-limited, while a Titan mission might have a MERlike longevity. All of which is to say that I don't see any sense in prioritizing exploration while isolating science interest as the only factor. I'd much rather see a helluva mission to any of these worlds before an incremental follow-on to any of the others.

So let me get this straight: the "outer planets folks" are pondering a New Frontier-class mission that wasn't even recommended in the Decadal Survey (i.e., the Titan concept you note above) while a subset of them are invoking the same Decadal Survey that lists Europa as the highest priority non-Mars Flagship-class target?

Sure. Such a mission would never get done this decade, so it's not incompatible with their citing the decadal survey. (No follow-on mission to Titan should really even be started until Cassini is done anyway, unless it lasts more than double its design lifetime.) Their argument is that this kind of mission should at least be talked about before they talk about landing on Titan (also not mentioned in the decadal survey), which is what Lunine was arguing for.

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